Telephone-transmitter.



Patented Jan. 19 1915.

C. G. TERHU N B. TELEPHONE TRANSMITTER. APPLICATION FILED 001233. 1913.

l/vi blesses CHARLES CLAY 'rnmunn'nnrnam sourn nano'ra.

TELEPHONE-TRANSMITTER.

Specification of Letters Patent.

Patented an. 19, 1915.

, Application filed October as, 1913. Serial No. 796,911.

To all whom it may concern Be it known that 1, CHARLES CLAY TER- HUNE, acitizen of the United States, residing at Platte, in the county ofCharles Mix and State of South Dakota, have invented certain new anduseful Improvements in Telephone-Transmitters; and I do hereby declarethe following to be a full, clear, and exact description of theinvention, such as will enable others skilled in the art to which itappertains to make and use the same.

This invention relates to telephone transmitters, and more particularlyto a permanent magnet attachment adapted to be se cured to telephones ofstandard types having iron diaphragm.

The principal object of the invention is the provision of a permanentmagnet in connection with the diaphragm of a transmitter, whereby thesound waves actuating the diaphragm are assisted by the action of themagnet, in compressing the granular carbon of the transmitter, themagnet also exerting a tension on the diaphragm thereby preventing eddyvibrations and side tones, and

for this reason the attachment maybe found 1 of great advantage whenused with a telephone transmitter of-factories orv other noisy places. I

Another object of this invention is to pro.- 'vide a device of the classdescribed, which willbe simple," durable, efficient in operation I andinexpensive to manufacture.

With these and other objects in view the inventiomresides in theconstruction, combination, and arrangement of parts, hereinafter morefully described and claimed and illustrated in the accompanying drawing,in whichjlike characters of reference indicate like parts throughout thefigures, of

' which,

Figure 1 represents a perspective view of atelephone transmitter'lookingfrom the back of the same, the housing 'havingbeen removed, and showingthe invention as a plied thereto, 'Fig. '2-represents an end e evationalview of the magnet, Fig. 3 represents a bottom plan-view thereof, Fig. 4represents a vertical, transverse sectional view through a telephonetransmitter showing the invention as applied thereto.

- Referring more particularly to the drawing it will be seen that theinvention which comprises a permanent magnet 5, has been shown assecured by means of a clip 6 to the bridge 7 of an ordinary granularcarbon,

top of the magnet, and the clip has its endsv bent as at 10 to lie aainst the bridge at one end thereof, said 0, ip being secured by meansof screws 11 and 12, the formerextending through one end portion 10 ofthe clip into the bridge, and the latter extending through the oppositeend portion 14 of the clip, through the bridge near one end thereof andinto the casing 13 of the transmitter. Although I have described themagnet as being horse-shoe shaped, it will be understood that the shapeandproportion of the magnet may be varied to conform with therequirements of transmitters of different types, without departing fromthe spirit of the invention. I It will be seen by this construction thatthe ends of the magnet will tend to assist in actuating the diaphragm inpressing the granular carbon 1-1 and will tend to prevent any vibrationsand side tones by the diaphragm, and it has been found byfiexperimentthat the magnet may be used to good advantage for local or long distancework. Although I have described the preferred embodiment of myinvention, I may desire to make such changes in the construction,

of a bridge spaced from said diaphragm, an

arch formed intermediate the ends of said bridge, a permanent magnetpartially inclosing said arch and a clip arching over said magnetclamping it to said bridge and to the casing of the transmitter.

,2. ln'a combination with a granular carbon transmitter having an irondiaphragm, a. bridge spaced from said diaphragm, an

arch formed integral \vith said bridge, a,

permanent magnet, partially inclosing said arch and a clip embracingsaid magnet carbon therein, a permanent magnet partially inclosing saidarch and said granular carbon, and means for securing said magnet to thebridge and to the. casing of the transmitter;

4. In combination with a granular carbon transmitter having an irondiaphragm, of a permanent magnet, of a'transmitter bridge and of aclamp, said clamp being attached at one end to said bridge, archingoversaid magnet, clamping it to said bridge, and to the casing of atransmitter.

5. -The combination with a granular carbon transmitter, having an'irondiaphragm of a bridge to said transmitter, an arch formed integral withsaid bridge to permit of thepositioning of the granular carbon therein,a permanent magnet partially in-' closing said arch and said granularcarbon,

and a clip arching over said magnet clamping it to said bridge and tothe casing of the transmitter. 1 v g In testimony whereof I have signedmy name to this specification in the presence of two subscribingwitnesses.

CHAS. CLAY TERHUNE.

Witnesses:

H. K. HELGESON,

L. SANFORD.

